MELVILLE, N.Y.--(BUSINESS WIRE)--Sep 7, 2007 - OSI Pharmaceuticals,
Inc. (Nasdaq: OSIP) today provided a summary of selected data from
over 58 studies involving the Company's lead product, Tarceva(R),
presented during the 12th World Congress on Lung Cancer (WCLC) held
September 2-6 in Seoul, Korea. Tarceva is currently approved in the
United States as monotherapy for the treatment of patients with
locally advanced or metastatic non-small cell lung cancer (NSCLC)
after failure of at least one prior chemotherapy regimen, and in
combination with gemcitabine chemotherapy for the first-line
treatment of locally advanced, unresectable, or metastatic
pancreatic cancer.

"The Tarceva studies presented at the World Congress on Lung
Cancer reinforce the role that Tarceva may have across a broad
range of patients with NSCLC, including its investigational use as
a first-line treatment and at a higher dose in current smokers,"
said Gabriel Leung, President, (OSI) Oncology. "Of particular
interest is a study that suggests that a higher dose of Tarceva may
improve drug exposure for lung cancer patients who continue to
smoke. The dosing and pharmacokinetic data from this now closed
study will be submitted to the FDA for consideration in the
label."

Following are summaries of highlighted presentations:

Randomized Phase I Pharmacokinetic Study of Two Doses of
Erlotinib after Failure of Prior Chemotherapy in Patients with
Advanced NSCLC Who Continue to Smoke - P. Woll, et al. (Poster
PD3-2-3)

Data from other studies have suggested that following treatment
with Tarceva at 150mg/day, current smokers in the studies had lower
exposure, experienced less rash and achieved less survival benefit
than former or never smokers. It has been hypothesized that this
may have been due, in part, to induction of liver metabolism
enzymes by tobacco use and that a higher dose of Tarceva, if
feasible, may improve outcome in current smokers.

A two-part study was conducted to investigate the feasibility of
escalating Tarceva to define the maximum tolerated dose (MTD) in
smokers and evaluate pharmacokinetics (PK) in patients dosed at
this MTD versus the standard Tarceva dose of 150mg/day. Part I of
the study identified the MTD in NSCLC patients who continue to
smoke as 300mg/day. Part II data indicated that there was a
dose-dependent increase in the systemic Tarceva exposure in current
smokers and that levels of Tarceva in current smokers at 300mg/day
was similar to historical data (BR.21 trial) for never/former
smokers at 150mg/day. During the initial 14-day dosing period,
toxicity was similar for the 150mg/day and 300mg/day doses.

Erlotinib as a Single-agent in the Treatment of Patients with
Advanced or Metastatic NSCLC and Good Performance Status- P.
Garrido, et al. (Poster P3-083)

Data were presented from this prospective, open-label,
non-randomized Phase II study called TargeT summarizing the
clinical outcome in a group of NSCLC patients who had undergone a
variety of prior therapeutic interventions and who presented with
good ECOG performance status (0-1). A total of 1,153 patients with
PS ECOG 0-1 were included in this analysis. Of the 731 patients who
had measurable disease and were evaluable for response, 10 had a
complete response (CR), 131 had a partial response (PR), 286 had
stable disease (SD) and 304 had progressive disease (PD). The
overall response rate was 19.3% and disease control rate was 58.4%.
Median time to progression (TTP) was 4.0 months and median survival
was 7.2 months. In the analysis the absence of smoking history and
line of treatment were associated with longer time to progression
and survival. The subgroup of non-smokers reached a median overall
survival of 13.4 months. The most common adverse events related to
Tarceva were rash and diarrhea. No unexpected toxicities were
observed.

Another prospective analysis of the TargeT trial evaluated
unselected chemotherapy-naive patients not suitable for
conventional first-line chemotherapy. From a study population of
461 patients, 259 were evaluable for response: 8 CR, 75 PR, 101 SD,
and 75 PD, for an overall response rate (RR) of 32.1% and disease
control rate (CR+PR+SD) of 71%. Median TTP was 6.6 months and
median survival time was 7.0 months. In the analysis, smoking
history was the most significant factor for TTP and survival. The
most common adverse events related to Tarceva were rash and
diarrhea. No unexpected toxicities were observed.

New data from the Phase III TRUST study, the largest and longest
ongoing study of Tarceva in NSCLC, show that NSCLC patients treated
with Tarceva in routine clinical practice are experiencing
comparable efficacy to what was seen in the landmark, pivotal BR.21
study, the study that earned Tarceva its approval in over 80
countries.

In the TRUST study, data from 6,181 patients reported a median
overall survival of 7.5 months. Patients in the study were able to
receive Tarceva at the full therapeutic dose. The most frequent
adverse event was rash (70%).

These new data further underscore Tarceva's potential across a
broad range of lung cancer patients. Data on the remaining patients
in the TRUST study are still being analyzed and will be presented
at a later date.

MERIT is the largest prospective RNA expression profiling study
ever conducted in second-line NSCLC. This Phase II, multi-center,
open-label study is designed to identify potential biomarkers that
may predict clinical benefit for NSCLC patients treated with
Tarceva.

Results from the 264 patients evaluable for efficacy supported
the use of Tarceva as an effective alternative to chemotherapy for
patients with advanced NSCLC. An objective response was seen in 36
patients (13.6%) and 83 patients (31.4%) had clinical benefit.
Median overall survival was 7.6 months; median progression-free
survival was 11.3 weeks. The most common adverse events were rash,
diarrhea, dyspnoea and anorexia.

OSI, together with its partners Genentech and Roche, are
committed to determining which patients may derive the greatest
benefit from Tarceva and have several ongoing studies designed to
support the development of clinically validated diagnostic tests
that may help oncologists appropriately select patients for
treatment with Tarceva.

Additional Tarceva Information

Tarceva was approved by the FDA in November 2004 as monotherapy
for the treatment of patients with locally advanced or metastatic
non-small cell lung cancer (NSCLC) after failure of at least one
chemotherapy regimen. Results from two earlier large, randomized,
placebo-controlled Phase III clinical trials in first-line advanced
NSCLC patients showed no clinical benefit with concurrent
administration of Tarceva with doublet platinum-based chemotherapy
(carboplatin and paclitaxel or gemcitabine and cisplatin) and its
use is not recommended in that setting.

There have been infrequent reports of serious Interstitial Lung
Disease (ILD)-like events, including fatalities, in patients
receiving Tarceva for treatment of NSCLC, pancreatic cancer or
other advanced solid tumors. In the pancreatic cancer trial, other
serious adverse events associated with Tarceva plus gemcitabine and
which may have included fatalities, were myocardial
infarction/ischemia, cerebrovascular accident and microangiopathic
hemolytic anemia with thrombocytopenia. When receiving Tarceva
therapy, women should be advised against becoming pregnant or
breastfeeding. Tarceva is pregnancy category D. The most common
side effects in patients with NSCLC receiving Tarceva monotherapy
150 mg were rash and diarrhea. The most common side effects in
patients with pancreatic cancer receiving Tarceva 100 mg plus
gemcitabine were fatigue, rash, nausea, anorexia and diarrhea.

Tarceva is a small molecule designed to target the human
epidermal growth factor receptor 1 (HER1) pathway, one of the
factors critical to cell growth in NSCLC and other solid tumors.
HER1, also known as EGFR, is a component of the HER signalling
pathway, which plays a role in the formation and growth of numerous
cancers. Tarceva is designed to inhibit the tyrosine kinase
activity of the HER1 signaling pathway inside the cell, which may
block tumor cell growth. Tarceva is the only HER1/EGFR-targeted
therapy proven to significantly prolong survival in second-line
NSCLC as a single agent.

In November 2005, the U.S. Food and Drug Administration (FDA)
approved the use of Tarceva in combination with gemcitabine for the
first-line treatment of patients with locally advanced,
unresectable or metastatic pancreatic cancer in patients who have
not received previous chemotherapy. Tarceva is the first drug in a
Phase III trial to have shown a significant improvement in overall
survival when added to gemcitabine chemotherapy as an initial
treatment for pancreatic cancer.

OSI Pharmaceuticals is committed to "shaping medicine and
changing lives" by discovering, developing and commercializing
high-quality and novel pharmaceutical products designed to extend
life and/or improve the quality of life for patients with cancer
and diabetes/obesity. The Company's oncology programs are focused
on developing molecular targeted therapies designed to change the
paradigm of cancer care. OSI's diabetes/obesity efforts are
committed to the generation of novel, targeted therapies for the
treatment of type 2 diabetes and obesity. OSI's flagship product,
Tarceva(R) (erlotinib), is the first drug discovered and developed
by OSI to obtain FDA approval and the only EGFR inhibitor to have
demonstrated the ability to improve survival in both non-small cell
lung cancer and pancreatic cancer patients in certain settings. OSI
markets Tarceva through partnerships with Genentech, Inc. in the
United States and with Roche throughout the rest of the world. For
additional information about OSI, please visit
http://www.osip.com.

This news release contains forward-looking statements. These
statements are subject to known and unknown risks and uncertainties
that may cause actual future experience and results to differ
materially from the statements made. Factors that might cause such
a difference include, among others, the completion of clinical
trials, the FDA review process and other governmental regulation,
OSI's and its collaborators' abilities to successfully develop and
commercialize drug candidates, competition from other
pharmaceutical companies, the ability to effectively market
products, and other factors described in OSI Pharmaceuticals'
filings with the Securities and Exchange Commission.